It threw me at first hearing......"he's gone to hospital", instead of "he's gone to the hospital". We, Americans, always insert the "the" naturally.
Also "pissed" over here means angry, not drunk.
In the UK, "He's gone to the hospital" would mean that he has gone to a specific hospital, but not necessarily for treatment (indeed, a logical response to the statement wculd be "Why?", as in has he gone for treatment, or for another reason? He might even be a doctor or nurse off to provide treatment!).. 'To hospital' means that someone has gone for hospital based treatment, without defining precisely which hospital they've gone too.
If you add "off", as in "I'm pissed off", then it can mean angry over here too, in a fed up sort of way!